ECSS-E-ST-31-02C

12 December 2012

Space engineering

Two-phase heat transport

equipment

ECSS Secretariat

ESA-ESTEC

Requirements & Standards Division

Noordwijk, The Netherlands

ECSS-E-ST-31-02C

12 December 2012

Foreword

This Standard is one of the series of ECSS Standards intended to be applied together for the

management, engineering and product assurance in space projects and applications. ECSS is a

cooperative effort of the European Space Agency, national space agencies and European industry

associations for the purpose of developing and maintaining common standards. Requirements in this

Standard are defined in terms of what shall be accomplished, rather than in terms of how to organize

and perform the necessary work. This allows existing organizational structures and methods to be

applied where they are effective, and for the structures and methods to evolve as necessary without

rewriting the standards.

This Standard has been prepared by the ECSS-E-ST-31-02C Working Group, reviewed by the ECSS

Executive Secretariat and approved by the ECSS Technical Authority.

Disclaimer

ECSS does not provide any warranty whatsoever, whether expressed, implied, or statutory, including,

but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty

that the contents of the item are error-free. In no respect shall ECSS incur any liability for any

damages, including, but not limited to, direct, indirect, special, or consequential damages arising out

of, resulting from, or in any way connected to the use of this Standard, whether or not based upon

warranty, business agreement, tort, or otherwise; whether or not injury was sustained by persons or

property or otherwise; and whether or not loss was sustained from, or arose out of, the results of, the

item, or any services that may be provided by ECSS.

Published by: ESA Requirements and Standards Division

ESTEC, P.O. Box 299,

2200 AG Noordwijk

The Netherlands

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Change log

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First issue

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Table of contents

Change log ................................................................................................................. 3

Introduction ................................................................................................................ 7

1 Scope ....................................................................................................................... 8

2 Normative references ............................................................................................. 9

3 Terms, definitions and abbreviated terms .......................................................... 10

3.1 Terms defined in other standards ........................................................................... 10

3.2 Terms specific to the present standard ................................................................... 10

3.3 Abbreviated terms................................................................................................... 14

4 TPHTE qualification principles ............................................................................ 15

4.1 TPHTE categorization ............................................................................................. 15

4.2 Involved organizations ............................................................................................ 15

4.3 Generic requirements in this standard .................................................................... 16

4.4 Processes, number of qualification units ................................................................. 17

4.5 Thermal and mechanical qualification ..................................................................... 17

4.5.1 Temperature range ................................................................................... 17

4.5.2 Mechanical qualification ............................................................................ 19

5 Requirements ........................................................................................................ 21

5.1 Technical requirements specification (TS) .............................................................. 21

5.1.1 General ..................................................................................................... 21

5.1.2 Requirements to the TS ............................................................................ 21

5.1.3 Requirements for formulating technical requirements ................................ 22

5.2 Materials, parts and processes ............................................................................... 23

5.3 General qualification requirements ......................................................................... 23

5.3.1 Qualification process ................................................................................. 23

5.3.2 Supporting infrastructure – Tools and test equipment ............................... 23

5.4 Qualification process selection ............................................................................... 23

5.5 Qualification stage .................................................................................................. 25

5.5.1 General ..................................................................................................... 25

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5.5.2 Quality audits ............................................................................................ 26

5.5.3 Qualification methods ................................................................................ 26

5.5.4 Full and delta qualification programme ...................................................... 28

5.5.5 Performance requirements ........................................................................ 28

5.6 Qualification test programme .................................................................................. 30

5.6.1 Number of qualification units ..................................................................... 30

5.6.2 Test sequence .......................................................................................... 31

5.6.3 Test requirements ...................................................................................... 34

5.6.4 Physical properties measurement ............................................................. 37

5.6.5 Proof pressure test .................................................................................... 38

5.6.6 Pressure cycle test .................................................................................... 38

5.6.7 Burst pressure test .................................................................................... 38

5.6.8 Leak test ................................................................................................... 39

5.6.9 Thermal performance test ......................................................................... 40

5.6.10 Mechanical tests ....................................................................................... 42

5.6.11 Thermal cycle test ..................................................................................... 44

5.6.12 Aging and life tests .................................................................................... 44

5.6.13 Gas plug test ............................................................................................. 45

5.6.14 Reduced thermal performance test ............................................................. 45

5.7 Operating procedures ............................................................................................. 46

5.8 Storage ................................................................................................................... 46

5.9 Documentation ....................................................................................................... 46

5.9.1 Documentation summary .......................................................................... 46

5.9.2 Specific documentation requirements........................................................ 46

Annex A (normative) Technical requirements specification (TS) – DRD ............ 49

Annex B (normative) Verification plan (VP) – DRD ............................................... 52

Annex C (normative) Review-of-design report (RRPT) - DRD .............................. 55

Annex D (normative) Inspection report (IRPT) – DRD .......................................... 57

Annex E (normative) Test specification (TSPE) – DRD ........................................ 59

Annex F (normative) Test procedure (TPRO) – DRD ............................................ 62

Annex G (normative) Test report (TRPT) – DRD ................................................... 65

Annex H (normative) Verification report (VRPT) – DRD ....................................... 67

Bibliography ............................................................................................................. 69

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Figures

Figure 3-1: Tilt definition for HP ............................................................................................ 13

Figure 3-2: Tilt definition for LHP .......................................................................................... 13

Figure 4-1: Categories of TPHTE (two-phase heat transport equipment) ............................. 16

Figure 4-2: Figure-of-merit (G) for some TPHTE fluids ......................................................... 18

Figure 4-3: Definition of temperature and performance ranges for a HP ............................... 19

Figure 5-1: Selection of qualification process ....................................................................... 25

Figure 5-2: Qualification test sequence for HP ..................................................................... 32

Figure 5-3: Qualification test sequence for CDL ................................................................... 33

Tables

Table 5-1: Categories of two-phase heat transport equipment according to heritage

(derived from ECSS-E-ST-10-02C, Table 5-1) ................................................... 24

Table 5-2: Allowable tolerances ............................................................................................ 35

Table 5-3: Measurement accuracy ....................................................................................... 37

Table 5-4: Equipment resonance search test levels ............................................................. 43

Table 5-5: Sinusoidal vibration qualification test levels ......................................................... 43

Table 5-6: Random vibration qualification test levels ............................................................ 44

Table 5-7: TPHTE documentation ........................................................................................ 48

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Introduction

This Standard is based on ESA PSS-49, Issue 2 “Heat pipe qualification

requirements”, written 1983, when the need for heat pipes in several ESA

projects had been identified. At that time a number of European development

activities were initiated to provide qualified heat pipes for these programmes,

which culminated in a first heat pipe application on a European spacecraft in

1981 (MARECS, BR-200, ESA Achievements - More Than Thirty Years of

Pioneering Space Activity, ESA November 30, 2001), followed by a first major

application on a European communication satellite in 1987 (TV-SAT 1, German

Communication Satellites).

ESA PSS-49 was published at a time, when knowledge of heat pipe technology

started to evolve from work of a few laboratories in Europe (IKE, University

Stuttgart, EURATOM Research Centre, Ispra). Several wick designs, material

combinations and heat carrier fluids were investigated and many process

related issues remained to be solved. From today’s view point the qualification

requirements of ESA PSS-49 appear therefore very detailed, exhaustive and in

some cases disproportionate in an effort to cover any not yet fully understood

phenomena. As examples the specified number of qualification units (14), the

number of required thermal cycles (800) and the extensive mechanical testing

(50 g constant acceleration, high level sine and random vibration) can be cited.

The present Standard takes advantage of valid requirements of ESA PSS-49, but

reflects at the same time today’s advanced knowledge of two-phase cooling

technology, which can be found with European manufacturers. This includes

experience to select proven material combinations, reliable wick and container

designs, to apply well-established manufacturing and testing processes, and

develop reliable analysis tools to predict in-orbit performance of flight

hardware. The experience is also based on numerous successful two-phase

cooling system application in European spacecraft over the last 20 years.

Besides stream-lining the ESA PSS-49, to arrive at today’s accepted set of heat

pipe qualification requirements, the following features have also been taken

into account:

• Inclusion of qualification requirements for two-phase loops (CPL, LHP),

• Reference to applicable requirements in other ECSS documents,

• Formatting to recent ECSS template in order to produce a document,

which can be used in business agreements between customer and

supplier.

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Scope

This standard defines requirements for two-phase heat transportation

equipment (TPHTE), for use in spacecraft thermal control.

This standard is applicable to new hardware qualification activities.

Requirements for mechanical pump driven loops (MPDL) are not included in

the present version of this Standard.

This standard includes definitions, requirements and DRDs from ECSS-E-ST-10-

02, ECSS-E-ST-10-03, and ECSS-E-ST-10-06 applicable to TPHTE qualification.

Therefore, these three standards are not applicable to the qualification of

TPHTE.

This standard also includes definitions and part of the requirements of ECSS-E-

ST-32-02 applicable to TPHTE qualification. ECSS-E-ST-32-02 is therefore

applicable to the qualification of TPHTE.

This standard does not include requirements for acceptance of TPHTE.

This standard may be tailored for the specific characteristic and constrains of a

space project in conformance with ECSS-S-ST-00.

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Normative references

The following normative documents contain provisions which, through

reference in this text, constitute provisions of this ECSS Standard. For dated

references, subsequent amendments to, or revision of any of these publications

do not apply. However, parties to agreements based on this ECSS Standard are

encouraged to investigate the possibility of applying the more recent editions of

the normative documents indicated below. For undated references, the latest

edition of the publication referred to applies.

ECSS-S-ST-00-01

ECSS system - Glossary of terms

ECSS-E-ST-31 Space engineering - Thermal control general

requirements

ECSS-E-ST-32

Space engineering - Structural general requirements

ECSS-E-ST-32-01

Space engineering- Fracture control

ECSS-E-ST-32-02 Space engineering - Structural design and verification

of pressurized hardware

ECSS-Q-ST-70 Space product assurance - Materials, mechanical parts

and processes

EN 9100:2009 Aerospace series - Quality management systems -

Requirements for Aviation, Space and Defense

Organizations

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Terms, definitions and abbreviated terms

3.1 Terms defined in other standards

For the purpose of this Standard, the terms and definitions from ECSS-E-ST-00-01

apply.

For the purpose of this standard, the following terms and definitions from

ECSS-E-ST-10-02 apply:

analysis

qualification stage

review-of-design (ROD)

For the purpose of this standard, the following terms and definitions from

ECSS-E-ST-32-02 apply:

burst pressure

differential pressure

external pressure

internal pressure

leak-before-burst (LBB)

pressure vessel (PV)

pressurized hardware (PH)

proof test

3.2 Terms specific to the present standard

3.2.1 capillary driven loop (CDL)

TPL, in which fluid circulation is accomplished by capillary action (capillary

pump)

NOTE See TPL definition in 3.2.21.

3.2.2 capillary pumped loop (CPL)

CDL with the fluid reservoir separated from the evaporator and without a

capillary link to the evaporator

NOTE See CDL definition in 3.2.1.

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3.2.3 constant conductance heat pipe (CCHP)

heat pipe with a fixed thermal conductance between evaporator and condenser

at a given saturation temperature

NOTE See heat pipe definition in 3.2.7.

3.2.4 dry-out

depletion of liquid in the evaporator section at high heat input when the

capillary pressure gain becomes lower than the pressure drop in the circulating

fluid

3.2.5 effective length

heat pipe length between middle of evaporator and middle of condenser for

configurations with one evaporator and one condenser only

NOTE Used to determine the heat pipe transport

capability (see 3.2.10).

3.2.6 exposure temperature range

maximum temperature range to which a TPHTE is exposed during its product

life cycle and which is relevant for thermo-mechanical qualification

NOTE 1 The internal pressure at the maximum temperature

of this range defines the MDP for the pressure

vessel qualification of a TPHTE.

NOTE 2 The extreme temperatures of this range can be

below freezing and / or above critical temperatures

of the working fluid.

NOTE 3 In other technical domains, this temperature range

is typically called non-operating temperature

range (see clause 4 for additional explanation).

3.2.7 heat pipe (HP)

TPHTE consisting of a single container with liquid and vapour passages

arranged in such a way that the two fluid phases move in counter flow

NOTE 1 See TPHTE definition in 3.2.20.

NOTE 2 The capillary structure in a heat pipe extends over

the entire container length.

3.2.8 heat pipe diode (HPD)

heat pipe, which transports heat based on evaporation and condensation only

in one direction

NOTE See heat pipe definition in 3.2.7.

3.2.9 loop heat pipe (LHP)

CDL with the fluid reservoir as integral part of the evaporator

NOTE 1 See CDL definition in 3.2.1.

NOTE 2 The reservoir can be separated, but has a capillary

link to the evaporator.

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3.2.10 heat transport capability

maximum amount of heat, which can be transported in a TPHTE from the

evaporator to the condenser

NOTE For heat pipes it is the maximum heat load

expressed in [Wm] (transported heat x effective

length).

3.2.11 maximum design pressure (MDP)

maximum allowed pressure inside a TPHTE during product life cycle

NOTE The product life cycle starts after acceptance of

the product for flight.

3.2.12 mechanical pump driven loop (MPDL)

TPL, in which fluid circulation is accomplished by a mechanical pump

NOTE See TPL definitions in 3.2.21.

3.2.13 product life cycle

product life starting from the delivery of the TPHTE hardware until end of

service live

3.2.14 reflux mode

operational mode, where the liquid is returned from the condenser to the

evaporator by gravitational forces and not by capillary forces

3.2.15 start-up

operational phase starting with initial supply of heat to the evaporator until

nominal operational conditions of the device are established

3.2.16 sub-cooling

temperature difference between average CDL reservoir temperature and the

temperature of the liquid line at the inlet to the reservoir

NOTE The average CDL reservoir temperature

represents the saturation temperature inside the

reservoir.

3.2.17 thermal performance temperature range

temperature range for which a TPHTE is thermally qualified

NOTE In the thermal performance temperature range

a thermal performance map exists.

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3.2.18 tilt for HP

height of the evaporator (highest point) above the condenser (lowest point)

during ground testing

NOTE This definition is valid for a configuration with

one evaporator and one condenser (see Figure

3-1).

condenser

evaporator

Figure 3-1: Tilt definition for HP

3.2.19 tilt for LHP

height of the evaporator (highest point) above the reservoir (lowest point)

during ground testing

NOTE See Figure 3-2.

Figure 3-2: Tilt definition for LHP

3.2.20 two-phase heat transport equipment (TPHTE)

hermetically closed system filled with a working fluid and transporting thermal

energy by a continuous evaporation/condensation process using the latent heat

of the fluid

NOTE 1 A fluid evaporates in the heat input zone

(evaporator) and condenses in the heat output

zone (condenser).

NOTE 2 This is in contrast to a single-phase loop where the

sensible heat of a liquid is transported (a liquid

heats up in the heat input zone and cools down in

the heat output zone).

3.2.21 two-phase loop (TPL)

TPHTE with physically separated vapour and liquid transport lines forming a

closed loop

NOTE See TPHTE definition in 3.2.20.

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3.2.22 variable conductance heat pipe (VCHP)

heat pipe with an additional non-condensable gas reservoir allowing a variable

thermal conductance between evaporator and condenser

NOTE 1 See heat pipe definition in 3.2.7.

NOTE 2 The variation in thermal conductance is generally

accomplished by regulating the volume of a non-

condensable gas plug reaching into the condenser

zone, which in turn varies the effective condenser

length.

NOTE 3 The variation of the gas volume can be performed

by active or passive means.

3.3 Abbreviated terms

The following abbreviations are defined and used within this standard:

Abbreviation

Meaning

CCHP

constant conductance heat pipe

CDL

capillary driven loop

CPL

capillary pumped loop

CTE

coefficient of thermal expansion

DRD

document requirements definition

heat pipe

HPD

heat pipe diode

LBB

leak before burst

LHP

loop heat pipe

MDP

maximum design pressure

MPDL

mechanical pump driven loop

MSPE

metallic special pressurized equipment

NDI

non-destructive inspection

pressurized hardware

ROD

review-of-design

SPE

special pressurized equipment

TCS

thermal control (sub)system

TPHTE

two-phase heat transport equipment

TPL

two-phase loop

technical requirement specification

VCHP

variable conductance heat pipe

verification plan

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TPHTE qualification principles

4.1 TPHTE categorization

TPHTE are considered special pressurized hardware, as defined in clause 3.

Requirements of ECSS-E-ST-32-02 are included in this Standard for this reason.

The TPHTE are categorized in Figure 4-1 according to their design and

functional principle.

Heat pipes consist of a single container with a capillary structure extending

over the entire container length. Liquid and vapour passages are arranged in

such a way that the two fluid phases move in counter flow.

Capillary driven loops (CDL) have separate evaporator and condenser sections,

which are connected by dedicated vapour and liquid tubing. At least one

capillary structure is located in the evaporator section, which serves as capillary

pump to circulate the fluid in a true loop configuration.

The mechanically pumped two-phase loop (MPDL) has a configuration, which

is similar to the CDL, except that the circulation of the fluid is accomplished by

a mechanical pump.

NOTE Requirements for MPDL are not included in the

present version of this Standard.

4.2 Involved organizations

The qualification process of TPHTE is generally carried out by a specialized

equipment manufacturer (called in this document “supplier”) and controlled by

the qualification authority, which is called in this document the “customer”.

The qualification activity is embedded in the supplier’s product assurance and

quality organization and in most cases the supplier's quality assurance plan has

been established and approved for space activities independently from the

TPHTE qualification process specified in this document. It is the task of the

supplier’s PA authority to introduce / approve adequate product assurance

provisions at his subcontractor(s). The existence of an approved PA Plan is

precondition for commencing qualification activities.

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Figure 4-1: Categories of TPHTE (two-phase heat transport equipment)

4.3 Generic requirements in this standard

The present document provides generic, i.e. not project specific requirements

for formal qualification of TPHTE. It is therefore important to select overall and

enveloping qualification requirements in order to support a maximum of

spacecraft application without the need for delta qualification.

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4.4 Processes, number of qualification units

The qualification of TPHTE is based on qualified manufacturing processes (e.g.

cleaning, surface treatment, welding and leak testing) and covers in general the

following areas:

• Performance over long operation time (compatibility between fluid and

wall material, space radiation, leak tightness)

• Mechanical performance (strength, pressurized hardware)

• Thermal performance (e.g. heat transport capability, start-up behaviour,

heat transfer coefficients)

In this context the number of TPHTE units to be produced for the qualification

program are evaluated and selected by the supplier. There are no general

applicable sources, which specify the minimum of units to be used to undergo

identical qualification testing in order to arrive at a successful qualified

product. The question to be answered for each TPHTE configuration is: How

many identical units need to be built and tested in order to verify that

production processes provide reproducible performance results.

The following are possible selection criteria:

• Experience of the manufacturer in production of similar products,

• Simplicity of the configuration,

• TPHTE design features, which have inherent capability for good

repeatability of the production processes (e.g. simple axial grooved heat

pipes).

This Standard specifies the number of needed units submitted to the

qualification process for configurations, which are currently used in several

spacecraft applications. It is recommended that the supplier performs the

selection for other configurations and provide argumentation to the customer

for agreement of his choice.

Compared to full qualification of a new product the number of units can be

reduced for delta qualification of an existing but modified product.

4.5 Thermal and mechanical qualification

4.5.1 Temperature range

In contrast to most of electronic equipment the performance of a TPHTE varies

with its operating temperature, because properties of the used heat carrier are

temperature dependent. For heat pipes as an example, important fluid

properties can be grouped into a figure-of-merit (G), which is the product of

surface tension, heat of vaporization and liquid density divided by the liquid

viscosity (for more information see references in Bibliography). G is plotted for

some fluids over the temperature in Figure 4-2. The heat transport capability of

a capillary pumped loop is proportional to these curves.

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Figure 4-2: Figure-of-merit (G) for some TPHTE fluids

Generally, the applicable temperature range of a TPHTE is subdivided into a

thermally and a mechanically relevant regime.

The thermal performance temperature range, which is used for thermal

qualification, is defined within the theoretical operating temperature range,

confined by the freezing and the critical temperature of the used fluid. Lower

and upper temperature limits of the qualification range are selected in such a

way that a useful map of thermal performance data can be established. Within

this range the maximum transport capability for qualification will be

determined. For a specific space application the operating temperature range

(within the thermal performance temperature range) and the maximum

required heat transport capability are specified.

For thermo-mechanical qualification the temperature range is relevant, to which

the device is exposed to during the life cycle. In most cases this exposure

temperature range is wider than the above-mentioned thermal performance

temperature range. The minimum temperature of this range can be below the

freezing temperature of the used heat carrier and it is important to take into

account possible damage caused by the freezing or thawing effects. The upper

exposure temperature can be even above the critical temperature of the heat

carrier. This temperature determines in general the maximum internal pressure

for design and qualification of the device.

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The mentioned temperature ranges and associated heat transport capabilities

are illustrated in Figure 4-3.

Legend

max,qual

Maximum transport capability for qualification

max,acc

Maximum transport capability for acceptance (specified for a specific project)

, T

Freezing and critical temperature of a selected fluid

P, min,

P, max

Minimum and maximum performance temperature

Ac, min,

Ac, max

Minimum and maximum acceptance temperature (specified for a specific project)

P,min  T P,max Performance temperature range

Ac,min  T Ac,max Acceptance temperature range (specified for a specific project)

Figure 4-3: Definition of temperature and performance ranges for a HP

4.5.2 Mechanical qualification

TPHTE are classified as pressurized component and relevant mechanical

requirements are specified in ECSS-ST-E-32-02 and are applied in the present

Standard for all TPHTE types.

For qualification of a TPHTE as pressurized component the main characteristic

is the internal pressure, which varies in relation to the exposure temperature of

the unit (temperature dependent saturation pressure of the heat carrier liquid).

ECSS-ST-E-32-02 specifies qualification requirements for heat pipes (see figure

4.12). The present Standard selects qualification requirements for TPHTE,

which have seen proof pressure tests ≥ 1,5 MDP. Testing is the preferred

method rather than qualification by fracture control analysis.

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For qualifying a TPHTE with respect to external mechanical environment the

following mechanical tests are considered:

• Constant or static acceleration

• Sine vibration

• Random vibration

For these tests the qualification unit needs to be rigidly mounted to the test

equipment (vibration table). However, such mounting provisions can have only

reduced similarity to real applications in spacecrafts and the meaningfulness of

such tests is, therefore, very often reason for discussion under experts. For heat

pipes it is common understanding not to perform these tests on long heat pipe

profiles for the following reasons:

• The length of the test heat pipe is adapted to the test equipment and is

therefore shorter as in many realistic spacecraft applications.

• The application of heat pipe is often for embedding them in sandwich

structures. Mechanical loads for these applications are quite different as

can be simulated with a rigidly fixed single heat pipe profile.

• Several capillary structures, in particular axial groove heat pipes, are

quite insensitive to mechanical loads and tests as suggested in existing

procedures can be unnecessary.

For many TPHTE applications (in particular for devices with simple capillary

structures, e.g. axial grooves) the formal mechanical qualification can be

therefore performed with the first structural model on satellite level. In case the

risk for such a late qualification is high, pre-qualification can be performed on

unit or part level in particular for the following cases:

• The TPHTE, in particular a heat pipe, has a capillary structure, which is

sensitive towards mechanical loads, e.g. arterial wick. In such a case a

short piece of the heat pipe profile is selected for mechanical qualification

testing (sine, random vibration).

• An evaporator of a LHP or CPL can be separately tested (sine, random

vibration) to verify that mechanical requirements are met.

• Equally this can be true for a two-phase loop condenser, in particular for

configurations where the condenser tubing is embedded into a structural

panel.

The Standard does not therefore not specify at which model level vibration

testing is to be performed. The supplier and customer are asked to agree on a

logical qualification plan, which may include testing at higher than equipment

level.

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Requirements

5.1 Technical requirements specification (TS)

5.1.1 General

a. The qualification process shall be based on a technical requirements

specification, approved by the customer.

NOTE Usually the technical specification evolves from

the functional requirements of the customer

and defines the technical performances for the

proposed solution as part of a business

agreement.

b. The technical requirements specification specified in 5.1.1a shall be

written in accordance with DRD in Annex A.

5.1.2 Requirements to the TS

a. The specification shall be identifiable, referable and related to a TPHTE

product.

b. The following entity shall be responsible for the TS:

1. the supplier for a generic TPHTE specification, which is not related

to a specific application;

2. the customer for a specific TPHTE specification, which is related to

a specific application.

NOTE A delta qualification can be necessary, if the

generic specification does not completely meet

the requirements for a specific application.

c. Each technical requirement shall be separately stated.

d. Abbreviated terms used in requirements shall be defined in a dedicated

section of the specification.

e. The technical requirements shall be consistent and not in conflict with the

other requirements within the specification.

f. The technical requirements shall not be in conflict with other

requirements contained in business agreement documents.

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g. The specification shall be complete in terms of applicable technical

requirements and reference to applicable documents.

h. The specification shall be under configuration management.

i. Quantity of units required for the qualification process shall be specified

in the TS.

NOTE TS exclude requirements such as cost, methods

of payment, time or place of delivery.

5.1.3 Requirements for formulating technical

requirements

a. Each technical requirement shall be described in quantifiable terms.

b. The technical requirements shall be unambiguous.

c. Each technical requirement shall be unique.

d. A unique identifier shall be assigned to each technical requirement.

e. Each technical requirement shall be separately stated.

f. A technical requirement shall be verifiable using one or more approved

verification methods.

g. The tolerance shall be specified for each parameter/variable.

NOTE The technical requirement tolerance is a range

of values within which the conformity to the

requirement is accepted.

h. Technical requirements should be stated in performance or “what-is-

necessary” terms, as opposed to “how-to" perform a task, unless the exact

steps in performance of the task are essential to ensure the proper

functioning of the product.

i. Technical requirements should be expressed in a positive way, as a

complete sentence (with a verb and a noun).

j. The verbal form “shall” shall be used whenever a provision is a

requirement.

k. The verbal form “should” shall be used whenever a provision is a

recommendation.

l. The verbal form “may” shall be used whenever a provision is a

permission.

m. The verbal form “can” shall be used to indicate possibility or capability.

n. The following terms shall not be used in a TS requirement: “and/or”,

“etc”, “goal”, “shall be included but not limited to”, “relevant”,

“necessary”, “appropriate”, “as far as possible”, “optimize”, “minimize”,

“maximize”, “typical”, “rapid”, “user-friendly”, “easy”, “sufficient”,

“enough”, “suitable”, “satisfactory”, adequate”, “quick”, “first rate”,

“best possible”, “great”, “small”, “large”, and “state of the art”.

ECSS-E-ST-31-02C

12 December 2012

5.2 Materials, parts and processes

a. Materials, parts and processes for TPHTE to be qualified shall be

documented in the following lists (see Table 5-7):

1. Declared materials list

2. Declared mechanical parts list

3. Declared processes list

5.3 General qualification requirements

5.3.1 Qualification process

a. The qualification stage shall be completed before launch.

5.3.2 Supporting infrastructure – Tools and test

equipment

a. Tools to be used to support the qualification process shall be validated

for their intended use.

b. The validation shall be performed under expected environmental

conditions and operational constraints.

c. Compatibility of tools and test equipment interfaces with flight

qualification hardware shall be verified by test.

d. Calibration of laboratory equipment shall be verified prior to their use.

e. Tools and test equipment that is modified and used in a new application

shall be re-verified according to 5.3.2a to 5.3.2d.

f. Test facilities, tools and instrumentation shall be designed to avoid

adverse effects on the qualification objectives.

NOTE Examples of these are: Thermocouples, strain

gauges, heater mounting, cooling devices,

support structures.

5.4 Qualification process selection

a. The scope of the qualification process shall be adapted to the

qualification heritage of the product.

b. For categorization of the heritage the product categories of Table 5-1 shall

be used.

c. The qualification process shall be structured according to Figure 5-1.

ECSS-E-ST-31-02C

12 December 2012

Table 5-1: Categories of two-phase heat transport equipment according to heritage

(derived from ECSS-E-ST-10-02C, Table 5-1)

Category

Description Qualification programme

Remarks related to the present

Standard

A Off-the-shelf product without

modifications and

 The product is qualified to

requirements at least as severe as

those imposed by the actual

technical specification

 The product is produced by the

same manufacturer and using

identical tools and manufacturing

processes

None

B Off-the-shelf product without

modifications.

However:

 The product is qualified to

requirements less severe or

different to those imposed by the

actual technical specification

 The product is produced by a

different manufacturer or using

different tools and manufacturing

processes

 The product has substitution parts

and materials with equivalent

reliability *)

Delta qualification

programme, decided on a

case-by-case basis in

agreement between the

customer and the supplier

This category relates for example to

TPHTE hardware, which is identical

to already qualified hardware but has

been qualified to lower mechanical

loads or narrower operating

temperature ranges as required by an

actual project.

The category relates also to situations,

where TPHTE manufacturing

technology is transferred from a

qualified supplier to a new

manufacturer.

*) Any substitution parts and

materials fulfilling the same

procurement specification does not

require delta-qualification.

C Off-the-shelf product with design

modifications

Delta or full qualification

programme, decided on a

case-by-case basis depending

on the impact of the

modification in agreement

between the customer and the

supplier

Examples for category C are:

Heat pipes with identical capillary

structure but different diameters,

smaller bent radius,

CDL with different fluid line

configurations or dimensions or

different condenser configurations

(radiator lay out).

D New designed and developed product. Full qualification programme. Applicable for any new developed

TPHTE, including existing systems

with new capillary structures or

material combinations.

ECSS-E-ST-31-02C

12 December 2012

Figure 5-1: Selection of qualification process

5.5 Qualification stage

5.5.1 General

a. Qualification shall demonstrate that the design of the TPHTE meets the

requirements of the technical specification.

NOTE The qualification can be supported by in-orbit

demonstration to verify requirements, which

are affected by zero-g environment.

TPHTE to be

qualified

Category A

equipment?

No qualification

programme required

Category B

equipment?

Delta qualification

programme

(Clause 5.5.4.2)

Category C

equipment?

Delta qualification

programme

(Clause 5.5.4.2)

or Full qualification

programme

(Clause 5.5.4.1)

Category D

equipment

Full qualification

programme

(Clause 5.5.4.1)

Review-of-design

(Clause 5.5.3.4)

Yes

Similarity analysis

(Clause 5.5.3.3.2)

Similarity analysis

(Clause 5.5.3.3.2)

For category definition see Table 5-1.

ECSS-E-ST-31-02C

12 December 2012

b. When a requirement is verified by qualification at lower level, the

traceability to the lower level verification evidence shall be provided.

NOTE This concerns manufacturing processes as well

as parts, materials and sub-units of a TPHTE.

c. Formal close-out of qualification at lower level shall be performed prior

to close-out at higher level.

5.5.2 Quality audits

a. The supplier shall allow quality audits in support to the qualification

process in accordance with EN 9100-2009 clause 4.6.4.2.

b. Quality audits shall be conducted such that the supplier’s know-how and

proprietary data are protected.

NOTE As a general rule audits should be performed

by quality assurance personnel of the customer

and not by experts in the field.

5.5.3 Qualification methods

5.5.3.1 Overview

a. A verification plan (VP) shall be prepared in conformance with the DRD

in Annex B and agreed with the customer.

b. The qualification of TPHTE shall be accomplished by one or more of the

following verification methods:

1. Test (including demonstration), as specified in 5.5.3.2.

2. Analysis (including similarity), as specified in 5.5.3.3.

3. Review-of-design, as specified in 5.5.3.4.

4. Inspection, as specified in 5.5.3.5.

c. The selected qualification methods shall be defined in a verification plan

specified in 5.5.3.1a.

5.5.3.2 Test

a. Verification by test shall consist of measuring product performance and

functions under representative simulated environments.

b. All safety critical functions shall be verified by test.

c. Qualification shall be carried out on hardware, which is representative of

the end item in terms of design, materials, tooling and methods.

d. TPHTE subject to qualification test shall be manufactured applying

qualified processes.

ECSS-E-ST-31-02C

12 December 2012

5.5.3.3 Analysis

5.5.3.3.1 General

a. Verification by analysis shall consist of performing theoretical or

empirical evaluation using techniques agreed with the customer.

b. Analysis shall be performed to predict specified performance parameter

of the TPHTE.

c. Analytical prediction results shall be correlated with qualification test

results.

NOTE Result correlations lead to software tool

validation, which can reduce follow-on

qualification processes.

d. Discrepancies between analytical prediction and test results shall be

analysed in order to demonstrate that the objective of the qualification is

not compromised.

e. Mechanical and thermal performance analysis and test prediction shall

be documented in a dedicated report in conformance with ECSS-E-ST-31,

Annex C.

NOTE Analysis and test prediction can be split in two

documents.

5.5.3.3.2 Similarity

a. For a product that is similar to already qualified products, a similarity

analysis shall be performed to identify differences requiring

complementary qualification activities.

b. Qualification by similarity shall not be performed on a product that has

been previously qualified by similarity.

5.5.3.4 Review-of-design (ROD)

a. For verification by ROD existing records and evidence shall be used to

demonstrate that requirements are met.

NOTE Existing records and evidence are validated

design documents, approved design reports,

technical description, engineering and

manufacturing drawings.

b. Verification by ROD shall be documented in a Review-of-Design report

in conformance with the DRD in Annex C.

5.5.3.5 Inspection

a. For verification by inspection visual determination of physical

characteristics shall be used to demonstrate that requirements are met.

NOTE Physical characteristics include constructional

features, hardware conformance to document

drawing and workmanship requirements,

physical conditions.

ECSS-E-ST-31-02C

12 December 2012

b. Verification by inspection shall be documented in an Inspection Report in

conformance with the DRD in Annex D.

5.5.4 Full and delta qualification programme

5.5.4.1 Full qualification programme

a. Equipment for which a full qualification programme is required as per

Table 5-1 shall be qualified by test according to clause 5.5.3.2 and 5.6 and

by analysis according to clause 5.5.3.3.

5.5.4.2 Delta qualification programme

a. Equipment for which a delta qualification programme is required as per

Table 5-1 shall undergo a delta qualification programme, which is a

subset of the full qualification programme of clause 5.5.4.1.

b. The delta qualification programme shall be selected on a case-by-case

basis and based on the modifications to existing qualified hardware.

c. The delta qualification programme shall be agreed with the customer.

5.5.5 Performance requirements

5.5.5.1 Generic requirements

a. The following generic performance characteristics of a TPHTE shall be

determined and verified against specified data:

1. Ability to sustain the combination of the predicted worst

mechanical loads:

(a) External mechanical loads.

(b) Internal loads due to the saturation pressure of the heat

carrier fluid within the TPHTE exposure temperature range.

CTE mismatch within the TPHTE exposure temperature

range.

(d) Loads imposed by volume change due to freezing/thawing

of the heat carrier within the TPHTE exposure temperature

range.

2. Safe life item and fatigue-life demonstration

(a) Safe life item demonstration, performed by analysis or test

or both in conformance with ECSS-E-ST-32-01 for TPHTE

not submitted to a proof pressure or for which the proof

factor used in the proof pressure test is less than 1,5.

(b) Fatigue-life demonstration, performed by analysis or test or

both in conformance with ECSS-E-ST-32 for TPHTE for

ECSS-E-ST-31-02C

12 December 2012

which the proof factor used in the proof pressure test is

equal or larger than 1,5.

3. Thermal parameters:

(a) Minimum and maximum heat transport capability over the

TPHTE thermal performance temperature range.

NOTE For heat pipes only the maximum heat

transport capability is of interest.

(b) Evaporator heat flux over the TPHTE thermal performance

temperature range.

(d) Overall thermal resistance of the device.

4. Operational characteristics

(a) Maximum heat load applied in one step at discrete

temperatures over the specified range.

(b) Start-up behaviour from frozen conditions, if the exposure

temperature range includes freezing of the working fluid.

of the working fluid.

5. Leak-before-burst.

6. Lifetime performance:

(a) Long-term compatibility between fluid and wetted materials

(materials in contact with the fluid).

(b) Space radiation effects in order to demonstrate that fluid de-

composition does not adversely affect specified TPHTE

performance during the product life cycle.

5.5.5.2 Specific requirements

a. For CCHP the following specific performance characteristics shall be

determined and verified against specified data:

1. Reduction of transport capability due to heat pipe bending at the

minimum specified radius.

2. Reduction of transport capability due to tilt (see Figure 3-1).

NOTE To item 1: The minimum bending radius is

defined by the supplier.

b. For VCHP, the following specific performance characteristics shall be

determined and verified against specified data:

1. The characteristics specified in 5.5.5.2a,

2. Maximum transport capability in fully-on conditions,

3. Heat leak from condenser to evaporator in off-mode,

4. Thermal resistance between condenser and reservoir,

ECSS-E-ST-31-02C

12 December 2012

5. Ability to regulate the evaporator temperature with passive and

active methods.

NOTE Passive methods include devices with non-

heated gas reservoirs, active methods include

devices with heated/cooled gas reservoirs.

c. For HP Diode, the following specific performance characteristics shall be

determined and verified against specified data.

1. The characteristics specified in 5.5.5.2a,

2. Maximum heat transport capability in forward mode,

3. Time and energy to move from forward to reverse mode,

4. Time and energy to move from reverse to forward mode,

5. Heat leak from condenser to evaporator in reverse mode.

d. For CDL, the following specific performance characteristics shall be

determined and verified against specified data

1. Minimum heat load applied under which start-up is possible over

the specified temperature range,

2. Sensitivity of the minimum heat load in relation to the thermal

mass attached to the evaporator,

3. Minimum heat load applied under which nominal operation is

possible over the specified temperature range,

4. Sub-cooling conditions to guarantee specified performance,

5. Impact on performance due to tilt (see Figure 3-2) and adverse

elevation (evaporator above condenser),

6. Heat leak from condenser to evaporator in off-mode,

7. Ability to regulate the evaporator temperature with passive and

active methods.

NOTE Passive methods include devices with passive

regulation (by-pass) valves in TPL. Active

methods include devices with heated/cooled

liquid reservoirs, heated regulation valves and

TPLs with thermo-electric cooler (TEC) on the

liquid reservoir.

5.6 Qualification test programme

5.6.1 Number of qualification units

a. The number of TPHTE units submitted to the qualification programme

test units shall be in accordance with Figure 5-2 and Figure 5-3.

ECSS-E-ST-31-02C

12 December 2012

5.6.2 Test sequence

a. Equipment for which a full qualification programme is required as per

Table 5-1 shall be verified by qualification testing according to the test

sequence as defined in Figure 5-2 for HP and Figure 5-3 for CDL.

b. For an equipment where a delta qualification programme is required as

per Table 5-1, the supplier shall derive from the test sequence of Figure

5-2 for HP and Figure 5-3 for CDL a reduced test sequence for delta

qualification.

c. The delta qualification sequence shall be agreed with the customer.

ECSS-E-ST-31-02C

12 December 2012

Figure 5-2: Qualification test sequence for HP

Manufacturing of qualification

hardware

according to documented processes

Reduced acceptance test of hardware

for qualification:

• Physical property measurement (5.6.4)

• Proof pressure test (5.6.5)

• Leak test (5.6.8)

• Gas plug test (5.6.13)

• Reduced thermal performance test

(5.6.14.1 to 5.6.14.4)

Selection of test item

configuration and quantity

(5.6.1)

Test item preparation

Heat Pipe:

5 functional units

• 3 units straight configuration

• 2 units bent configuration

2 units for material compatibility testing

2 pressure samples

Full thermal performance test

(5.6.9.1 to 5.6.9.4)

Mechanical test

(5.6.10)

Leak test

(5.6.8)

Thermal cycle test

(5.6.11)

Gas plug test

(5.6.13)

Reduced thermal performance

test (5.6.14.1 to 5.6.14.4)

Aging test

(5.6.12)

Full thermal performance test

(5.6.9.1 to 5.6.9.4)

Test plan and Qualification

Test Readiness Review

(5.6.3.1)

Functional tests

(3 straight, 2 bent)

Material compatibility tests

(2 units) (2 HP)

Pressure tests

(2 samples)

Pressure cycle test

(5.6.6)

Burst pressure test

(5.6.7)

Life test incl. Gas plug test

(5.6.12 & 5.6.13)

Qualification test programme

Reduced thermal

performance test

(

5.6.14.1 to 5.6.14.4)

Reduced thermal

performance test

(

5.6.14.1 to 5.6.14.4)

Leak test

(5.6.8)

Verification Report

(Table 5-7)

Post Test Review

(5.6.3.1b)

ECSS-E-ST-31-02C

12 December 2012

Figure 5-3: Qualification test sequence for CDL

Reduced acceptance test of hardware for

qualification:

● Physical property measurement (5.6.4)

● Proof test (5.6.5)

● Leak test (5.6.8)

● Reduced thermal performance test (5.6.14)

Full thermal performance test

(5.6.9.1 & 5.6.9.5)

Mechanical test

(5.6.10)

Leak test

(5.6.8)

Reduced thermal performance test

(5.6.14.1 & 5.6.14.5)

Thermal cycle test

(5.6.11)

Full thermal performance test

5.6.9.1 & 5.6.9.5)

Test plan and Qualification

Test Readiness Review

(5.6.3.1)

Functional tests

(1 CDL)

Material compatibility tests

(1 CDL)

Pressure tests

(1 sample)

Pressure cycle test

(5.6.6)

Burst pressure test

(5.6.7)

Life test

(5.6.12)

Qualification test programme

Reduced thermal performance test

(5.6.14.1 & 5.6.14.5)

Reduced thermal performance test

(5.6.14.1 & 5.6.14.5)

Verification Report

(Table 5-7)

Post Test Review

(5.6.3.1b)

Manufacturing of qualification hardware

according to documented processes

Selection of test item configuration and

quantity

(5.6.1)

Test item preparation

CDL:

1 functional unit

1 unit for material compatibility testing

1 unit as pressure sample

Leak test

(5.6.8)

ECSS-E-ST-31-02C

12 December 2012

5.6.3 Test requirements

5.6.3.1 Test specification and reviews

a. Before starting the qualification test campaign the following

preconditions shall be met:

1. Establishing of a test specification in conformance with the DRD in

Annex E,

2. Establishing of test procedures in conformance with the DRD in

Annex F, and

3. Conductance of test readiness review.

b. At completion of the test sequence a post-test review shall be conducted.

c. Test documentation shall be agreed with the customer.

5.6.3.2 Test conditions

5.6.3.2.1 Test tolerances

a. The test tolerances specified in Table 5-2 shall be applied to the nominal

test values specified.

b. For the purpose of 5.6.3.2.1a, test tolerances shall include test

instrumentation accuracy.

NOTE The tolerances specified in Table 5-2 are the

allowable ranges within which the test

parameters can vary. The values in the table are

inclusive of instrumentation accuracy.

ECSS-E-ST-31-02C

12 December 2012

Table 5-2: Allowable tolerances

Test parameters

Tolerances

1. Temperature

Low High

above +100 °C

min

−

max

−

-73 °C < T ≤ +100 °C

min

−

max

−

-100 K (-173 °C) < T ≤ 200 K (-73

± 2 K (2 °C)

40 K (-233 °C) < T ≤ 100 K (-173

± 1 K (1 °C)

10 K (-263 °C) ≤ T ≤ 40 K (-233

< 0,5 K (0,5 °C)

T< 10 K (-263

Tolerance to be defined case by case

2. Relative humidity

± 10 %

3. Pressure (in vacuum chamber)

> 1,3 hPa

± 15 %

1,3 10

-3

hPa to 1,3 hPa

± 30 %

< 1,3 10

-3

hPa

± 80 %

4. Acceleration

-0 / +10 %

5. Static Load

-0 / +10 %

6. Sinusoidal vibration

Frequency (20 Hz to 2000 Hz)

± 2 %

Amplitude

± 10 %

Sweep rate (Oct/min)

± 5 %

7. Random vibration

Frequency

± 5 % (or 1 Hz whichever is greater)

Amplitude (PSD)

20 Hz - 100 Hz (max control

bandwidth 10 Hz)

-1/ +3 dB

100 Hz - 1000 Hz (10 % of midband

frequency)

-1/ +3 dB

1000 Hz - 2000 Hz (max control

bandwidth 100 Hz)

± 3,0 dB

Random overall g r.m.s.

± 10%

ECSS-E-ST-31-02C

12 December 2012

Test parameters

Tolerances

8. Acoustic noise

Sound pressure level, Octave band centre

(Hz)

Test tolerances (dB)

31,5

-2/+4

-1/+3

125

-1/+3

250

-1/+3

500

-1/+3

1000

-1/+3

2000

-1/+3

Overall

-1/+3

9. Microvibration susceptibility

Quasi-static force or torque ± 5 % To be related to the external forces that are

applied to extrapolate the transfer functions

Dynamic forces ±10 % To be related to the external forces that are

applied to extrapolate the transfer functions

Sound-power (1/3 octave band centre

frequency)

32,5 Hz - 160 Hz

±3 dB

160 Hz – 10000 Hz

±2 dB

10. Shock

Response spectrum amplitude (1/12 octave

centre frequency)

Shock level

≤

3000 Hz

- 3, + 6 dB

≥ 3000 Hz

- 3, + 9 dB

Shock duration

≤

20 ms

0/+ 20 %

> 20 ms

0/+ 10 %

11. Solar flux

in reference plane

± 4 % of the set value

In reference volume

± 6 % of the set value

12. Infrared flux

Mean value

± 3 % on reference plane(s)

13. Test time

-0/+10 %

ECSS-E-ST-31-02C

12 December 2012

5.6.3.2.2 Measurement accuracy

a. The accuracy of test instrumentation shall be verified in accordance with

approved calibration procedures.

b. All test instrumentation shall be within the normal calibration period at

the time of the test.

Table 5-3: Measurement accuracy

Test parameters

Accuracy

1. Mass

± 0,1 %

2. Centre of gravity (CoG)

Within a 1 mm radius sphere

3. Moment of inertia (MoI)

± 3 %

4. Leak rate

± 10

-5

Pa m

-1

of Helium at 1013 hPa pressure

differential or at least a factor of two with respect

to the leak rate to be measured.

5.6.3.2.3 Test results

a. Test results shall be monitored and compared across major test sequences

for trends or evidence of anomalous behaviour of the test set up.

b. Test reports shall be established for each test performed in conformance

with the DRD in Annex G.

5.6.3.3 Test data management

a. Performance test, leak test and long duration test results shall be used to

perform trend analysis to detect long-term gradually increasing defects

and failures.

5.6.4 Physical properties measurement

a. The following properties of the test unit shall be measured, recorded and

compared to specification in relevant drawings:

1. Completeness of configuration,

2. Materials as specified,

3. Dimension of unit and interfaces,

4. Mass,

5. Flatness of heat input and heat output zones,

ECSS-E-ST-31-02C

12 December 2012

6. Fluid amount (from manufacturing records),

7. Centre of gravity,

8. Momentum of inertia.

NOTE The determination of centre of gravity and

moment of inertia can be performed by

analysis.

b. For the physical properties measurement the test unit shall not include

test specific items.

5.6.5 Proof pressure test

a. Proof pressure test shall be performed applying 1,5 times MDP as

specified in ECSS-E-ST-32-02 for duration of 15 minutes.

NOTE During manufacturing processes (e.g. curing of

panels with embedded heat pipes) the pressure

can be higher than MDP, as long as the unit

material stays in the elastic domain.

b. Pressure shall be generated on the sealed unit by increasing the

temperature of the unit and thus the saturation pressure of the heat

carrier fluid (hot proof pressure test).

NOTE When the pressure target leads to a

temperature higher than the critical

temperature than the cold pressure test (before

unit sealing) can be considered to reach the

proof pressure requirement and a reduced

proof factor can be accepted for the hot

pressure test on the sealed unit.

c. In cases where proof pressure test is not feasible, margins against

mechanical failure shall be verified by analysis in accordance with ECSS-

E-ST-32-02.

5.6.6 Pressure cycle test

a. The pressure cycle test shall consist of 2000 cycles between 1 bar and

MDP at ambient temperature.

b. The supplier shall analyse the number of cycles above the 2000 cycles, to

which the TPHTE can be exposed before reaching the Woehler curve.

5.6.7 Burst pressure test

a. Burst pressure test shall be performed applying 2,5 times MDP for

duration of 15 minutes.

b. No rupture or leak shall occur during burst pressure test.

ECSS-E-ST-31-02C

12 December 2012

c. Burst pressure test shall be carried out with burst pressure samples

manufactured from the same material batch and according to processes,

which are identical to the ones used for the functional qualification unit.

d. Burst pressure samples shall include all features of the flight

configuration.

NOTE For example representative bends, welds and

joints.

e. Burst pressure test shall be performed at the maximum exposure

temperature by increasing the internal pressure until the required burst

pressure is reached.

NOTE Burst pressure testing at lower temperatures

may be performed, when a factor

corresponding to differences in material

properties between test and maximum

exposure temperature is taken into account.

f. After the 15 minutes hold-time, the pressure shall be further increased

until rupture occurs and the pressure at rupture shall be recorded.

g. If burst pressure tests are performed at sub-unit level, the burst pressure

test processes shall include all parts of the product including all joints,

welds, end fittings.

NOTE For example, if it is performed at the level of

the evaporator or reservoir of a TPL.

5.6.8 Leak test

a. Leak test shall be performed at ambient temperature using a detection

method agreed with the customer.

b. The maximum leak rates versus pressure values shall be established

through a detailed analysis such that operation of the system is ensured

throughout the specified lifetime.

c. Leak rate of all TPHTE hardware shall conform to the level defined in

5.6.8b.

NOTE Pressurized hardware containing hazardous

fluids reach end of safe-life when leakage

occurs.

d. During the leak test, the pressure level shall be maintained for 30 minutes

as a minimum.

ECSS-E-ST-31-02C

12 December 2012

5.6.9 Thermal performance test

5.6.9.1 General

a. Thermal performance test results, obtained under 1-g conditions, shall be

correlated to predict 0-g (on-orbit) performance.

b. For thermal performance tests at ambient conditions, it shall be

demonstrated that the conditions specified in 5.6.9.1a do not have an

influence on in-orbit performance.

NOTE For a specific application the customer can

require a thermal performance test in vacuum.

c. During ground test the unit shall be insulated and the remaining heat

exchange with the environment shall be determined.

d. When establishing the maximum heat transport capability, the vapour

temperature shall be varied in increments within the specified

operational temperature range such that a performance over temperature

curve is generated.

e. For each temperature step, the temperatures along the length of the unit

shall be measured and recorded.

f. Maximum performance shall be declared, when temperature excursions

in the evaporator indicate the beginning of a non-nominal operational

condition.

NOTE Temperature excursions are generally caused

by dry-out conditions in the evaporator.

g. Temperature readings during performance testing in combination with

the applied heat load (corrected for heat exchange with the environment)

shall be used to determine heat transfer coefficients in the evaporator and

the condenser.

h. Performance shall be measured as function of the orientation of

evaporator versus condenser in the gravitational field.

i. Test evaluation and data correlation shall be performed for each test and

documented in a TCS analysis report in conformance with the DRD in

Annex C of ECSS-E-ST-31.

5.6.9.2 Specific tests for CCHP

5.6.9.2.1 Maximum heat transport capability

a. Maximum heat transport capability shall be measured with

1. Straight HP.

2. Bent HP.

3. Uniform heat input and output.

4. One-sided heat input and one-sided heat output, as follows:

(a) combination of heat input on top of the HP and heat output

on bottom of the HP (with respect to gravity),

ECSS-E-ST-31-02C

12 December 2012

(b) combination of heat input on bottom of the HP and heat

output on top of the HP (with respect to gravity), and

b. The supplier shall define performance degradation at the minimum

allowed bending radius.

5.6.9.2.2 Performance under tilt

a. The maximum heat transport capability shall be measured for tilt heights

from zero to a value at which the heat transport capability falls to a value

<5 % of the maximum heat transport capability (at the test temperature).

b. Measurement shall be performed at sufficient tilt intervals as to create a

smooth curve of performance over tilt height.

c. Test results at different tilt heights shall be extrapolated to zero tilt.

NOTE The graphical extrapolation of tilt performance

to zero tilt (horizontal position) is assumed to

be the zero-g (in-orbit) performance.

5.6.9.2.3 Start-up test

a. A start-up test at the minimum thermal performance temperature by

applying 50 % of the maximum heat load specified at that temperature

shall be performed and the time until nominal operation shall be

determined.

5.6.9.2.4 Start-up procedure

a. After a full depriming (emptying the capillary structure), a start-up

procedure shall be determined.

5.6.9.2.5 Performance in reflux mode

a. The heat transfer coefficients in the evaporator and condenser areas shall

be derived as a function of power input and temperature.

b. Test shall be performed by applying power at to the bottom of the liquid

pool and measuring the temperature profile along the pipe.

5.6.9.3 Specific tests for VCHP

a. For VCHP, the following tests shall be performed:

1. The tests specified in clause 5.6.9.2.1 to 5.6.9.2.4.

2. Aging tests before charging the device with the control gas.

3. Maximum heat transport capability with the gas front located

outside the condenser (between condenser and reservoir).

4. Residual conductance with the gas front outside the condenser

(between condenser and evaporator).

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5.6.9.4 Specific tests for HP Diode

a. For HP Diode, the following tests shall be performed:

1. The tests specified in clause 5.6.9.2.1 to 5.6.9.2.4.

2. A test to determine the time-to-shutdown of the HP Diode, as

follows:

(a) apply pre-defined heat loads to the nominal condenser;

(b) vary the vapour temperature in suitable increments within

the specified operational temperature range in order to

generate a smooth performance over temperature curve;

and 80 % of the derived Qmax in nominal mode for the

specific heat pipe profile;

(d) derive the energy needed for shutdown for each of the

above tests.

3. A test to determine the time to start-up the heat pipe diode, as

follows:

(a) apply pre-defined heat loads to the nominal evaporator;

(b) ensure that the pre-defined heat loads are 10 %, 30 %, 50 %

and 80 % of the derived Qmax in nominal mode for the

specific heat pipe profile.

5.6.9.5 Specific tests for CDL

a. Start-up with low power shall be verified by testing with and without

thermal inertia on the evaporator heater system.

b. The specified performance of a CDL shall be verified under the following

test conditions:

1. Simulation of large heat load variations (increase and decrease of

heat load).

2. Simulation of large condenser temperature variations.

3. Different orientations with respect to gravity including tilt for

LHP.

4. Different parasitic heat inputs in the liquid line and into the

reservoir.

NOTE to subbullet 3: For the tilt definition see Figure 3-2.

5.6.10 Mechanical tests

5.6.10.1 General

a. Sinusoidal, random vibration and shock tests shall be performed on

higher than unit level, if the supplier in agreement with the customer

demonstrates that tests at unit level produce unrealistic results.

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NOTE Tests are generally not meaningful for long heat

pipe profiles, for heat pipes, which are later

embedded in structural panels and for CDL, for

which the configuration in the intended

application cannot be represented on unit level

(for example: large distance between

evaporator and condenser).

b. Sinusoidal, random vibration and shock tests shall be performed on

component level in order to verify critical details of the device.

NOTE A deflection test to replace sinusoidal and

random testing can be agreed with the

customer. For example: TPHTE with capillary

structures, which have an inherent

characteristic to be damaged by mechanical

loads.

c. Sinusoidal and random vibration tests shall be performed for the three

orthogonal axes of the device.

d. Sinusoidal and random vibration tests shall be performed at the

maximum internal pressure, which the device is exposed to during

ascent.

e. A resonance search shall be performed before and after the sinusoidal

and random vibration test to determine resonance frequencies, as

specified in Table 5-4.

f. If meaningful and agreed with the customer constant acceleration and

acoustic tests shall be performed.

Table 5-4: Equipment resonance search test levels

Frequency (Hz)

Level

Sweep rate

5 to 2 000

0,5 g

2 octave per min

5.6.10.2 Sinusoidal vibration

a. The test levels and duration for the sinusoidal vibration test, for generic

equipment qualification, independent of the launcher or space element,

shall be as specified in Table 5-5.

Table 5-5: Sinusoidal vibration qualification test levels

Frequency

(Hz)

Level First frequency > 100 MHz First frequency

≤

100 MHz

5 to 21

11 mm (0 to peak)

No notching

With notching

21 to 60

20 g (0 to peak)

No notching

With notching

60-100

6 g (0 to peak)

No notching

With notching

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5.6.10.3 Random vibration

a. The test levels and duration for the random vibration test, for generic

equipment qualification, independent of the launcher or space element,

shall be as specified in Table 5-6.

Table 5-6: Random vibration qualification test levels

Location

Duration

Levels

Equipment located

on external panel

with unknown

location

Vertical

2,5 min/axis

(20 - 100) Hz

(100 - 300) Hz

(300 - 2 000) Hz

+3 dB/octave

PSD(M)

= 0,12 g

/Hz × (M+ 20 kg)/(M + 1 kg)

-5 dB/octave

Lateral

2,5 min/axis

(20 - 100) Hz

(100 - 300) Hz

(300 - 2 000) Hz

+3 dB/octave

PSD(M)

= 0,05 g

/Hz × (M+ 20 kg)/(M + 1 kg)

-5 dB/octave

Equipment not

located on external

panel

All axes

2,5 min/axis

(20 - 100) Hz

(100 - 300) Hz

(300 - 2 000) Hz

+3 dB/octave

PSD(M)

= 0,05 g

/Hz × (M+ 20 kg)/(M + 1 kg)

-5 dB/octave

Panel directly excited by payload acoustic environment.

Equipment vertical axis = perpendicular to fixation plane.

Equipment lateral axis = parallel to fixation plane.

M = equipment mass in kg, PSD = Power Spectral Density in g

/Hz.

5.6.11 Thermal cycle test

a. The thermal cycle test shall consist of 8 full cycles over the exposure

temperature range with a hold-time of 1 hour.

NOTE Cycle tests of TPHTE can be performed under

ambient conditions.

5.6.12 Aging and life tests

a. TPHTE shall be operated in a long duration life test as specified in 5.6.12b

in order to confirm the specified performance over the product life cycle.

NOTE Heat pipes are typically operated in reflux

mode.

b. For qualification purpose of the device the duration of the life test shall

be ≥ 8000 hours.

NOTE The life test should be extended beyond the

formal qualification programme.

c. Aging tests shall be performed in the functional test sequence as given in

Figure 5-2 with a duration of 300 hours.

d. Life and aging tests shall be performed at the maximum specified

operation temperature.

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e. The amount of produced non-condensable gas shall be determined

according to 5.6.13 in periodic intervals agreed with the customer, with

shorter intervals especially at the beginning for the life test.

f. Trend analyse according to 5.6.3.3 shall be performed in order to

determine the non-condensable gas content at the end of the product life

cycle.

g. The TPHTE supplier shall demonstrate that the non-condensable gas

content expected at end of product life cycle does not violate the specified

performance.

5.6.13 Gas plug test

a. The gas plug test shall be performed during aging and life tests under the

following condition:

1. Heat pipe mounted in reflux mode, i.e. vertical orientation with

evaporator at the lower end.

2. Condenser is instrumented with temperature sensors in short axial

distances.

3. Periodic check of axial temperature profile of the condenser end at

lowest operating temperature.

b. The non-condensable gas content shall be determined based on the

measured temperature profile.

c. It shall be demonstrated that non-condensable gas generation over the

lifetime meets the specification for lifetime performance.

5.6.14 Reduced thermal performance test

5.6.14.1 General

a. The reduced thermal performance test shall include the general tests

specified in 5.6.9.1.

5.6.14.2 Specific CCHP

a. CCHP shall be tested according to requirements 5.6.9.2.1a.1, 5.6.9.2.1a.2,

5.6.9.2.1a.3 and 5.6.9.2.1a.4 for one selected configuration.

b. For CCHP, the maximum heat transport capability shall be measured for

one tilt between 2,5 mm and 4 mm at two temperatures to be agreed with

the customer.

5.6.14.3 Specific VCHP

a. For VCHP, the following test shall be performed:

1. the test specified in 5.6.14.1 and 5.6.14.2;

2. Thermal performance at fully on condition.

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5.6.14.4 Specific HP diode

a. For HP diode, tests shall be performed as specified in clause to 5.6.9.4 at

one vapour temperature and with a heat load of 50 % of Qmax.

b. The test specified in 5.6.14.4a should be performed at 20 °C.

5.6.14.5 Specific CDL

a. Start-up with low and maximum power shall be verified for one

condenser sink temperature and by simulation of flight-representative

thermal inertia on the evaporator heater system.

5.7 Operating procedures

a. Operating procedures shall be established for all TPHTE hardware.

b. The procedures specified in 5.7a shall be compatible with the safety

requirements and personnel control requirements at the facility where

the operations are conducted.

c. Step-by-step instructions shall be written with such a detail to

unambiguously describe the operation.

5.8 Storage

a. When TPHTE hardware is put into storage they shall be protected

against:

1. exposure to adverse environments that can cause corrosion or

degrade the material;

2. mechanical damages.

b. When TPHTE hardware is put into storage, induced stresses due to

storage fixture constraints shall be avoided by storage fixture design.

5.9 Documentation

5.9.1 Documentation summary

Table 5-7 presents a summary of all documents required by the present

standard.

5.9.2 Specific documentation requirements

a. The following documents shall be written and agreed with the customer

before starting the qualification process.

1. technical requirements specification (TS);

2. verification plan (VP).

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b. Test procedures shall be established for each test performed.

NOTE Several procedures can be grouped in one

document.

c. Test reports shall be established for each test performed.

NOTE Several reports can be grouped in one

document.

d. The design and manufacturing file of the qualification hardware shall be

under configuration control and available for customer review.

e. The final outcome of the qualification process shall be documented in the

verification report (VRPT) in conformance with the DRD in Annex H,

and agreed with the customer.

NOTE A customer statement on the successful

completion of the qualification process is

recommended.

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Table 5-7: TPHTE documentation

Title of DRD DRD reference Calling requirement in this standard

and remarks

Technical requirements

specification

Annex A Requirement 5.1.1b

NOTE: Requirement 5.1.1a requires that the

customer approval is needed before starting

the qualification process.

Verification plan

Annex B

Requirement 5.5.3.1a

Review-of-design report

Annex C

Requirement 5.5.3.4b

Inspection report

Annex D

Requirement 5.5.3.5b

Declared materials list ECSS-Q-ST-70,

Annex B

Requirement 5.2a.1

Declared mechanical parts list ECSS-Q-ST-70,

Annex C

Requirement 5.2a.2

Declared processes list ECSS-Q-ST-70,

Annex D

Requirement 5.2a.3

Mechanical and thermal

performance analysis and test

prediction report

ECSS-E-ST-31,

Annex C

Requirement 5.5.3.3.1e

NOTE: The report can be split in two

documents.

Test specification

Annex E

Requirement 5.6.3.1a.1.

Test procedure Annex F Requirement 5.6.3.1a.2.

NOTE: Requirement 5.9.2b

requires one

procedure for each test. Several procedures

can be grouped in one document.

Test report Annex G Requirement 5.6.3.2.3b.

NOTE: Requirement 5.9.2c

requires one test

report for each test. Several reports can be

grouped in one document.

Test evaluation and data

correlation report

ECSS-E-ST-31,

Annex C

Requirement 5.6.9.1i

Verification report Annex H Requirement 5.9.2e

NOTE: This requirement requires that the

Verification report is agreed with the

customer.

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Annex A (normative)

Technical requirements specification

(TS) – DRD

A.1 DRD identification

A.1.1 Requirement identification and source document

This DRD is called from ECSS-E-ST-31-02, requirement 5.1.1b.

A.1.2 Purpose and objective

The technical requirements specification (TS) establishes the intended purpose

of a product, its associated constraints and environment, the operational and

performance features for each relevant situation of its life profile, and the

permissible boundaries in terms of technical requirements.

The TS expresses frozen technical requirements for designing and developing

the proposed solution to be implemented. These technical requirements, to be

met by the future solution, are compatible with the intended purpose of a

product, its associated constraints and environment, and the operational and

performance features for each relevant situation of its life profile.

The content of this DRD is taken “as is” from ECSS-E-ST-10-06 Annex A.

A.2 Expected response

A.2.1 Scope and content

<1> Introductions

a. The TS shall contain a description of the purpose, objective, content and

the reason prompting its preparation.

<2> Applicable and reference documents

a. The TS shall list the applicable and reference documents in support of the

generation of the document.

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<3> User’s need presentation

a. The TS shall present the main elements that characterize the user’s need

for developing the product as a background for those requirements that

are defined in detail in the dedicated section.

b. The TS shall put the product into perspective with other related products.

c. If the product is independent and totally self-contained, i.e. able to match

the final user’s need, it should be so stated here.

d. If the TS defines a product that is a component of a higher tier system,

the TS shall recall the related needs of that larger system and shall

describe the identified interfaces between that system and the product.

NOTE A non-exhaustive checklist of general questions

that should be answered at the early stages of

the TS is:

• What is the product supposed to do? It is

fundamental but critically important to

make sure that every actor has a complete

understanding of what the product has to

do.

• Who is going to use this product? It is

important to indicate who is going to use the

product, why they are going to use it and for

what it is going to be used.

<4> Selected concept / product presentation

a. The technical specification shall describe the concept, the expected

product architecture and the functioning principles on which it is based.

<5> Life profile description

a. The TS shall list and describe the different chronological situations of the

product’s life profile.

NOTE 1 For a spacecraft, the life profile includes:

• AIT related life events;

• transportation to launching area;

• conditioning and tests;

• installation on launcher;

• pre-launch phase;

• launching phase;

• self-transfer to its operating position;

• in-orbit functioning;

• end-of-life (e.g. de-orbitation).

NOTE 2 An identifier can be associated with each

situation in order to be able to link each

requirement to at least one situation in which it

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12 December 2012

applies. Such an approach enables sorting and

filtering of the requirements per situation.

<6> Environment and constraints description

a. The TS shall describe the different environments and constraints for each

situation in the life profile that the product is expected to encounter.

NOTE An identifier can be associated with each

product environment in order to be able to link

each requirement to at least the worst

environment to which it applies. Such an

approach enables sorting and filtering the

requirements per environment.

<7> Requirements

a. The TS shall list all the technical requirements necessary for the product

to satisfy the user’s needs.

NOTE Interfaces requirements can be rolled-out of the

TS in form an interface requirement document

(IRD), see ECSS-E-ST-10 Annex M.

b. The technical requirements shall be expressed according to ECSS-E-ST-

31-02 clauses 5.1.2 and 5.1.3.

NOTE For instance, for all TS and for each

requirement, the following characteristics have

been selected:

• identifiability;

• performance and methods used to

determine it;

• configuration management;

• traceability;

• tolerance;

• verification.

A.2.2 Special remarks

None.

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Annex B (normative)

Verification plan (VP) – DRD

B.1 DRD identification

B.1.1 Requirement identification and source document

This DRD is called up from ECSS-E-ST-31-02, requirement 5.5.3.1a.

B.1.2 Purpose and objective

The Verification Plan contains the overall verification approach, the model

philosophy, the product matrix, the verification strategies for the requirements

(the interrelation between different methods/levels/stages of verification to be

used to demonstrate status of compliance to requirements), the test, inspection,

analysis and review-of-design programme with the relevant activity sheets and

planning, the verification tools, the verification control methodology, the

involved documentation, the verification management and organization.

The content of this DRD is taken “as is” from ECSS-E-ST-10-02 Annex A.

B.2 Expected response

B.2.1 Scope and content

<1> Introduction

a. The VP shall contain a description of the purpose, objective, content and

the reason prompting its preparation.

b. Open issues, assumptions and constraints relevant to this document shall

be stated and described.

<2> Applicable and reference documents

a. The VP shall list the applicable and reference documents in support to

the generation of the document.

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<3> Definitions and abbreviations

a. The VP shall list the applicable dictionary or glossary and the meaning of

specific terms or abbreviations utilized in the document.

<4> Verification subject

a. The VP shall briefly describe the subject of the verification process.

<5> Verification approach

a. The VP shall describe the basic verification concepts and definitions

(methods, levels and stages).

<6> Model philosophy

a. The VP shall describe the selected models and the associated model

philosophy, product matrix.

<7> Verification Strategy

a. The VP shall describe the selected combination of the different

verification methods at the applicable verification levels and stages, in

general and for each requirement type/group (including software).

b. The allocation of the requirements to the specific verification tasks shall

be given.

<8> Verification programme

a. The VP shall document the verification activities and associated planning

in the applicable verification stages.

b. Analysis, review-of-design, inspection and test programmes should be

detailed through dedicated activity sheets, or through reference to the

AIT Plan.

<9> Verification tools

a. The VP shall describe high level definitions of the verification tools to be

used, such as S/W facilities, special tools, simulators, analytical tools.

<10> Verification control methodology

a. The VP shall describe the proposed methodology to be utilized for

verification monitoring and control including the use of a verification

data base.

<11> Documentation

a. The VP shall list the involved verification documents and describe their

content.

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<12> Organization and management

a. The VP shall describe the responsibility and management tools

applicable to the described verification process.

b. It shall describe the responsibilities within the project team, the relation

to product assurance, quality control and configuration control

(including anomaly handling and change control) as well as the

responsibility sharing with external partners.

c. The relevant reviews shall be planned and responsibilities described.

B.2.2 Special remarks

a. The Verification Plan may be combined with the AIT Plan in one single

AIV Plan.

NOTE In this case VP and AIT plans do not exist

anymore as single entities.

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Annex C (normative)

Review-of-design report (RRPT) - DRD

C.1 DRD identification

C.1.1 Requirement identification and source document

This DRD is called up from ECSS-E-ST-31-02, requirement 5.5.3.4b.

C.1.2 Purpose and objective

The review-of-design report describes each verification activity performed for

reviewing documentation.

The review-of-design report contains proper evidence that the relevant

requirements are verified and the indication of deviations.

The content of this DRD is taken “as is” from ECSS-E-ST-10-02 Annex D.

C.2 Expected response

C.2.1 Scope and content

<1> Introduction

a. The RRPT shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Open issues, assumptions and constraints relevant to this document shall

be stated and described.

<2> Applicable and reference documents

a. The RRPT shall list the applicable and reference documents in support to

the generation of the document.

<3> Definitions and abbreviations

a. The RRPT shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document with the

relevant meaning.

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<4> Review-of-design summary

a. The RRPT shall describe the review-of-design activity in terms of method

and procedures used.

<5> Conclusions

a. The RRPT shall summarize

1. the review-of-design results, including:

(a) the list of the requirements to be verified (in correlation with

the VCD),

(b) traceability to used documentation,

signature and date,

2. the comparison with the requirements; and

3. the verification close-out judgment.

b. Open issues shall be clearly stated and described.

C.2.2 Special remarks

None.

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Annex D (normative)

Inspection report (IRPT) – DRD

D.1 DRD identification

D.1.1 Requirement identification and source document

This DRD is called up from ECSS-E-ST-31-02, requirement 5.5.3.5b.

D.1.2 Purpose and objective

The inspection report describes each verification activity performed for

inspecting hardware or software.

The inspection report contains proper evidence that the relevant requirements

are verified and the indication of deviations.

The inspection report may be embedded in the Test Report if the verification by

Inspection is carried-out in combination with Testing.

The content of this DRD is taken “as is” from ECSS-E-ST-10-02 Annex E.

D.2 Expected response

D.2.1 Scope and content

<1> Introduction

a. The IRPT shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Open issues, assumptions and constraints relevant to this document shall

be stated and described.

<2> Applicable and reference documents

a. The IRPT shall list the applicable and reference documents in support to

the generation of the document.

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<3> Definitions and abbreviations

a. The IRPT shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document with the

relevant meaning.

<4> Inspection summary

a. The IRPT shall describe the product configuration data of the inspected

item.

<5> Conclusions

a. The IRPT shall summarize the:

1. inspection results, including:

(a) the list of the requirements to be verified (in correlation with

the VCD),

(b) traceability to used documentation,

(d) expected finding,

(e) conformance or deviation including proper references and

signature and date.

2. comparison with the requirements, and

3. verification close-out judgement.

b. Open issues shall be clearly stated and described.

D.2.2 Special remarks

None.

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Annex E (normative)

Test specification (TSPE) – DRD

E.1 DRD identification

E.1.1 Requirement identification and source document

This DRD is called from ECSS-E-ST-31-02, requirement 5.6.3.1a.1.

E.1.2 Purpose and objective

The test specification (TSPE) describes in detail the test requirements applicable

to any major test activity. In particular, it defines the purpose of the test, the test

approach, the item under test and the set-up, the required GSE, test tools, test

instrumentation and measurement accuracy, test conditions, test sequence, test

facility, pass/fail criteria, required documentation, participants and test

schedule.

Since major test activities often cover multiple activity sheets, the structure of

the TSPE is adapted accordingly.

The TSPE is used as an input to the test procedures, as a requirements

document for booking the environmental test facility and to provide evidence

to the customer on certain details of the test activity in advance of the activity

itself.

The TSPE is used at each level of the space system decomposition (i.e.

equipment, space segment element).

The TSPE provides the requirements for the activities identified in the AITP (as

defined in Annex A of ECSS-E-ST-10-03).

The TSPE is used as a basis for writing the relevant test procedures (as defined

in Annex F) and test report (as defined in Annex C of ECSS-E-ST-10-02).

In writing the test specification potential overlaps with the test procedure is

minimized (i.e. the test specification gives emphasis on requirements, the test

procedure on operative step by step instructions). For simple tests, merging

TSPE and TPRO is acceptable.

The content of this DRD is taken “as is” from ECSS-E-ST-10-03 Annex B.

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E.2 Expected response

E.2.1 Scope and content

<1> Introduction

a. The TSPE shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Any open issue, assumption and constraint relevant to this document

shall be stated and described.

<2> Applicable and reference documents

a. The TSPE shall list the applicable and reference documents in support to

the generation of the document.

<3> Definitions and abbreviations

a. The TSPE shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document.

<4> Requirements to be verified

a. The TSPE shall list the requirements to be verified (extracted from the

VCD) in the specific test and provides traceability where in the test the

requirement is covered.

<5> Test approach and test requirements

a. The TSPE shall summarize the approach to the test activity and the

associated requirements as well as the prerequisites to start the test.

<6> Test description

a. The TSPE shall summarize the configuration of the item under test, the

test set-up, the necessary GSE, the test tools, the test conditions and the

applicable constraints.

<7> Test facility

a. The TSPE shall describe the applicable test facility requirements together

with the instrumentation and measurement accuracy, data acquisition

and test space segment equipment to be used.

<8> Test sequence

a. The TSPE shall describe the test activity flow and the associated

requirements.

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b. When constraints are identified on activities sequence, the TSPE shall

specify them including necessary timely information between test steps.

<9> Pass/fail criteria

a. The TSPE shall list the test pass/fail criteria, including their tolerance, in

relation to the inputs and output.

b. In the TSPE, the error budgets and the confidence levels to be applied,

including tolerance, shall be specified.

<10> Test documentation

a. The TSPE shall list the requirements for the involved documentation,

including test procedure, test report and PA and QA records.

<11> Test organization

a. The TSPE shall describe the overall test responsibilities, participants to be

involved and the schedule outline.

NOTE Participation list is often limited to organisation

and not individual name.

E.2.2 Special remarks

None.

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Annex F (normative)

Test procedure (TPRO) – DRD

F.1 DRD identification

F.1.1 Requirement identification and source document

This DRD is called from ECSS-E-ST-31-02, requirement 5.6.3.1a.2.

F.1.2 Purpose and objective

The Test Procedure (TPRO) gives directions for conducting a test activity in

terms of description, resources, constraints and step-by-step procedure, and

provides detailed step-by-step instructions for conducting test activities with

the selected test facility and set-up in agreement with the relevant AITP and the

test requirements. It contains the activity objective, the applicable documents,

the references to the relevant test specification and the test facility

configuration, the participants required, the list of configured items under test

and tools and the step-by-step activities.

The TPRO is used and filled-in as appropriate during the execution and

becomes the “as-run” procedure.

The TPRO is prepared for each test to be conducted at each verification level.

The same procedure can be used in case of recurring tests.

It incorporates the requirements of the test specification (DRD Annex E) and

uses detailed information contained in other project documentation (e.g.

drawings, ICDs).

Several procedures often originate from a single test specification. In certain

circumstances involving a test facility (for example during environmental tests)

several test procedures can be combined in an overall integrated test procedure.

The “as-run” procedure becomes part of the relevant test report (see ECSS-E-

ST-10-02).

Overlaps with the test specification are minimized (see Annex E).

The content of this DRD is taken “as is” from ECSS-E-ST-10-03 Annex C.

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12 December 2012

F.2 Expected response

F.2.1 Scope and contents

<1> Introduction

a. The TPRO shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Any open issue, assumption and constraint relevant to this document

shall be stated and described.

<2> Applicable and reference documents

a. The TPRO shall list the applicable and reference documents in support to

the generation of the document.

<3> Definitions and abbreviations

a. The TPRO shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document.

<4> Requirements mapping w.r.t. the TSPE

a. The TPRO shall provide a mapping matrix to the TSPE giving traceability

towards the test requirement.

<5> Item under test

a. The TPRO shall describe the item under test configuration, including any

reference to the relevant test configuration list, and any deviation from

the specified standard.

b. The software version of the item under test shall be identified.

<6> Test set-up

a. The TPRO shall describe the test set-up to be used.

<7> GSE and test tools required

a. The TPRO shall identify the GSE and test tools to be used in the test

activity including test script(s), test software and database(s) versioning

number.

<8> Test instrumentation

a. The TPRO shall identify the test instrumentation, with measurement

accuracy, to be used, including fixtures.

ECSS-E-ST-31-02C

12 December 2012

<9> Test facility

a. The TPRO shall identify the applicable test facility and any data handling

system.

<10> Test conditions

a. The TPRO shall list the applicable standards, the applicable test

conditions, in terms of levels, duration and tolerances, and the test data

acquisition and reduction.

<11> Documentation

a. The TPRO shall describe how the applicable documentation is used to

support the test activity.

<12> Participants

a. The TPRO shall list the allocation of responsibilities and resources.

<13> Test constraints and operations

a. The TPRO shall identify special, safety and hazard conditions,

operational constraints, rules for test management relating to changes in

procedure, failures, reporting and signing off procedure.

b. The TPRO shall describe QA and PA aspects applicable to the test.

c. The TPRO shall contain a placeholder for identifying:

1. procedure variations, together with justification, and

2. anomalies.

<14> Step-by-step procedure

a. The TPRO shall provide detailed instructions, including expected results,

with tolerances, pass/fail criteria, and identification of specific steps to be

witnessed by QA personnel.

b. The step-by-step instructions may be organized in specific tables.

c. When the procedure is automated, the listing of the automated procedure

shall be documented to a level allowing consistency check with the TPRO

and the TPSE.

F.2.2 Special remarks

None.

ECSS-E-ST-31-02C

12 December 2012

Annex G (normative)

Test report (TRPT) – DRD

G.1 DRD identification

G.1.1 Requirement identification and source document

This DRD is called up from ECSS-E-ST-31-02, requirement 5.6.3.2.3b.

G.1.2 Purpose and objective

The test report describes test execution, test and engineering assessment of

results and conclusions in the light of the test requirements (including pass-fail

criteria).

The test report contains the scope of the test, the test description, the test article

and set-up configuration, and the test results including the as-run test

procedures, the considerations and conclusions with particular emphasis on the

close-out of the relevant verification requirements including deviations.

The content of this DRD is taken “as is” from ECSS-E-ST-10-02 Annex C.

G.2 Expected response

G.2.1 Scope and content

<1> Introduction

a. The TRPT shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Open issues, assumptions and constraints relevant to this document shall

be stated and described.

<2> Applicable and reference documents

a. The TRPT shall list the applicable and reference documents in support to

the generation of the document.

ECSS-E-ST-31-02C

12 December 2012

<3> Definitions and abbreviations

a. The TRPT shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document.

<4> Test results

a. The TRPT shall contain the test results with supporting data (including

the test execution dates, the as run procedure, and the test facility

results).

b. The TRPT shall contain the analysis of test data and the relevant

assessment.

c. The TRPT shall provide a synthesis of the test results.

<5> Anomalies

a. The TRPT shall include the list of deviations to the test procedure, the

nonconformance including failures and the problems.

<6> Conclusions

a. The TRPT shall summarize:

1. the test results, including:

(a) the list of the requirements to be verified (in correlation with

the VCD),

(b) traceability to used documentation,

signature and date).

2. the comparison with the requirements, and

3. the verification close-out judgment.

b. Open issues shall be clearly stated and described.

c. Separate test analyses shall be cross-referenced.

G.2.2 Special remarks

None.

ECSS-E-ST-31-02C

12 December 2012

Annex H (normative)

Verification report (VRPT) – DRD

H.1 DRD identification

H.1.1 Requirement identification and source document

This DRD is called up from ECSS-E-ST-31-02, requirement 5.9.2e.

H.1.2 Purpose and objective

The Verification Report is prepared when more than one of the defined

verification methods (see 5.5.3.1) is utilized to verify a requirement or a specific

set of requirements.

It reports the approach followed and how the verification methods were

combined to achieve the verification objectives.

The positive achievement constitutes the completion of verification for the

particular requirement.

The content of this DRD is taken “as is” from ECSS-E-ST-10-02 Annex F.

H.2 Expected response

H.2.1 Scope and content

<1> Introduction

a. The VRPT shall contain a description of the purpose, objective, content

and the reason prompting its preparation.

b. Open issues, assumptions and constraints relevant to this document shall

be stated and described.

<2> Applicable and reference documents

a. The VRPT shall list the applicable and reference documents in support to

the generation of the document.

ECSS-E-ST-31-02C

12 December 2012

<3> Definitions and Abbreviations

a. The VRPT shall list the applicable dictionary or glossary and the meaning

of specific terms or abbreviations utilized in the document with the

relevant meaning Verification subject.

<4> Verification results

a. The VRPT shall describe the verification approach, the associated

problems and results with reference to the relevant test, analysis,

review-of-design and inspection reports.

b. The VRPT shall identify the deviations from the verification plan.

<5> Conclusions

a. The VRPT shall list the requirements to be verified (in correlation with

the VCD).

b. The VRPT shall summarize verification results, the comparison with the

requirements and the verification close-out judgement.

c. Open issues shall be clearly stated and described.

H.2.2 Special remarks

None.

ECSS-E-ST-31-02C

12 December 2012

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System engineering general

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ECSS-E-ST-10-02

Space engineering - Verification

ECSS-E-ST-10-03

Space engineering - Testing

ECSS-E-ST-10-06 Space engineering - Technical requirements

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Heat Pipe Science and Technology, Taylor &

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